1. Field of the Invention
This invention relates to a video telephone in which images of telephoners as well as writings or drawings are alternately formed and transmitted.
2. Description of the Related Art
A well known type of video telephone disclosed in Japanese Laid Open Patent No. 61-179690 comprises a video camera and a monitoring display. Images of a telephoner are formed in the video camera and sent to another monitoring display of a telephonee, and images of the telephonee are given by the monitoring display of the telephoner.
Recently, a video telephone shown in FIG. 4 was disclosed, in which the images of the telephoner A as well as the writing or drawing B are alternately formed in a single video camera 3 and transmitted.
Provided on one side of a display stand 7 is a camera stand 15, on a top of which a pivot 16 is secured for a support arm 17 to be turned horizontally on the pivot 16, and further, a video camera 3 is secured to be turned vertically on another pivot 18, which is secured to the distal end of the arm 17.
To form the image of the telephoner A in the video camera 3, the video camera 3 is turned above a display 6 to become parallel to a direction indicated by arrow a, and positioned as indicated in solid lines in FIG. 4. When the image of the writing or drawing B is formed, the arm 17 is turned through an angle of 180.degree. in a direction of arrow b on the pivot 16 as indicated in chain-dotted lines in FIG. 4, and then, the video camera 3 is turned through an angle of 90.degree. in a direction of arrow c on the pivot 18 to become parallel to a direction indicated by arrow d. Thus, the image of the writing or drawing 8 is to be formed in the video camera 3.
However, in the video telephone shown in FIG. 4, the video camera 3 is required to travel rather a large distance between two positions where the images of the telephoner A and the writing or drawing B are formed, respectively. In addition, in the course of the travel, the video camera 3 is turned two times on the pivots 16 and 18.
Thus, the telephoner A is inconvenienced by moving the video camera 3 in order to take pictures alternately of himself A and of the writing or drawing B during telephoning, which wastes his time.
Moreover, a mechanism for moving the video camera 3, which comprises the support arm 17 and the two pivots 16 and 18, is complicated in structure, is rather expensive for manufacturing, and requires a large space for the support arm 17 to travel. In addition, movable portions, such as the pair of pivots 16 and 18 are apt to often break down, and also, the video camera itself is apt to break down because of being frequently moved.